My 991.1 GT3 RS has the Leather/Alcantara interior with GT silver stitching, I treated the leather interior with

TriNova Leather Conditioner and Cleaner

and a must say it gives the rather bland leather, a much deeper/more shiny appearance which not only makes it look better but gives a nice contrast with the Alcantara sections

 

and all the internal rear wheel arch panels too etc, it really uplifts the interior

 

For best results, it's a good idea to use a leather cleaner with a small soft brush, and wipe down with a soft white cloth to see what you are taking out. You would be very surprised!

Follow up with a leather conditioner and give it a bit of time to actually soak in.

Not recommended to use two in one (cleaner and conditioner) unless you don't really care for what you are cleaning that much.

I used swissvax with amazing results on all of my cars. It's pricey, but worth it as it goes a long way with incredible results.

 

My point is that as new there is very little contrast with the Alcantara and the (cheap) optioned leather under the expanse of the front windshield which looks very unappealing, in fact its scary on car which cost close to $300k

 

I know of Swissvax but its over promoted for what it is, the only reason I dared to do this in the GT3 RS is that I was SOOO impressed with the long lasting results in my 981 GTS